Radial pump



Sept. 13, 1938.- w, ERNST 2,130,299

RADIAL PUMP Filed Feb. 10, 1936 3' Sheets-Sheet l INVENTOR lmzn'e,se/vsr Sm +6MLM ATTORNEYS Sept. 13, 1938. w. ERNST 2,1 9

RADIAL PUMP Filed Feb. 10, 193 :5 sheets-sh et'z INVENTOR mu 7,52ie/vsr.

BY Q SMJZW #JW 67 65' ATTORNEYS I Patented Sept. 13, 1938 UNITED, STATESPATENT OFFICE Walter Ernst, Mount Gilead, Ohio, asslgnor to TheHydraulic Press Corporation, Inc., Wilmington, Del., a corporation 01'Delaware Application February 10, 19.36, Serial No. 63,146

. v 12 Claims.

This invention relates to hydraulic pumps or motors, and in particular,to a hydraulic pump having radial pistons and cylinders. One object ofthis invention is to provide a hydraulic pump or motor having a primaryrotor with radial cylinder bores, the pistons whereof engage segmentalcrosshead blocks, whichin turn, engage anti-friction bearing elementsmounted in a shift ring surrounding the entire assembly.

Another object is to provide such a pump or motor, wherein the head ofeach piston is rounded and rests in a recess in the inner side of theguide block.

Another object is to provide a pump or motor of this description,wherein the segmentalguide blocks are spaced apart from one another andseparately engage difierent anti-friction bearing elements disposedaround the inner surface of the shift ring, the latter serving as anouter bearing race for the anti-friction bearing elements.

,Another object is to provide a hydraulic pump or motor, wherein theradial pistons reciprocating in a radially bored primary rotor haverounded ends resting in tapered recesses in the inner sides of segmentalguide blocks so as to enable the pistons to rock back andforth in thetapered recesses, the outer sides of the guide blocks engagingroller'bearings held in place by a bearing race which is laterallymovable to serve also as a shift ring to vary the eccentricity betweenthe shift ring and the primary rotor,

and thereby to produce reciprocation of thepistons.

Another object is to provide a hydraulic pump or motor of the typepreviously described, wherein a second pump is coupled therewith toprovide super-charging for the first-mentioned pump,'

charging pump taken along the line 2-2 of Figure 1.

Figure 3 is a top plan view of the pump assembly shown in Figure 1.

Figure 4 is a left-hand end elevation of the pumpassembly shown inFigures 1 and 3.

Figure 5 is an enlarged cross section through the pintle of the mainpump, taken along the line 5-5 of Figure 1.

Figure 6 is a longitudinal, vertical section through the pump assemblyshown in Figure 1, taken along the axis of the main drive shaft andpintle.

Figure 7 is a .transverse section through the 10 main pump, taken alongthe line 'l-'|' of Figure 6.

Figure 8 is a left-hand end elevation of the pintle shown in Figure 9.

Figure 9 is a side elevation, partly in section, of the pintle used inthe radial or main pump of my invention.

Figure 10 is a right-hand end elevation of the pintle shown in Figure 9.

Figure 11 is a cross section through the pintle taken' along the linell--H'of Figure 9.

Figure 12 is a side elevation of a complete assembly of piston crossheadguide blocks.

Figure 13 is a cross section along the line l3-i3 of Figure 12.

Figure 14 is a perspective view of a piston employed in the pump ormotor of this invention.

Figure 15 is a perspective view of a modified form of piston, showing awrist pin for retaining the piston'in engagement with its crossheadguide block. I 30 Figure 16 is an enlarged cross section taken along theaxis of a piston, and showing the modified form of piston of Figure 15secured to its crosshead guide block.

General construction and circuit 35 Referring to the drawings in detail,Figures 1 and 6 show the pump assembly of this invention as consistingof a main pump, generally desig hated it], on the left-hand side of thefigures, 40 and a super-charging pump, generally designated ii, on theright-hand side thereof. The main pump is of the radial piston type. Thesupercharging pump may be of any suitable type, and is shown as a'gearpump. The two pumps are driven by a common drive shaft, and thesupercharging pump supplies pressure to the main pump so that thepistons are maintained in engagement with their crosshead guide blockseven during the suction strokes thereof.

The inlet I? (Figure 3) from the source of fluid, such as a tank, isconnected to the intake side of the super-charging pump H, from theoutlet side of which the pipe idruns to the inlet side of themain pumpit. A branch it offthe pipe is is 5 ton serving to shift the controldevice, for thepump and reduce its delivery when the outlet pressureexceeds a predetermined amount.

Main pump construction The main pump I0 is of the variable deliveryradial piston type, and is contained within the casing halves 20 and 2|,these being held together by the machine screws 22. The casing half 2|is supplied with a projecting portion 23, having a bore 24 which servesto support the pintle 25. The projecting portion 28 is provided with athreaded passage 26, serving as an outlet port and connected to theoutlet pipe I1. A similar threaded passage 21 connects the opposite sideof the projecting portion 28 with the inlet pipe IS. The passages 26 and21 lead inwardly so as to communicate with the ducts 28 and 29.respectively, leading to the outlet and inlet passages 20 and II of thepintle 25. From the threaded passage 22 the branch passage is leadstothe pilot line II. as shown in Figure 5. The outlet and inlet passages20 and SI lead to the transverse ducts 22- and 22, opening into thecutaway portions 24 and 25 near the mid-portion of the pintle. By thismeans fluid is conducted to and from the cylinders of the pump, ashereinafter explained.

Immediately adjacent the cutaway portions 24 and 25 the pintle 25 isprovided with an enlarged portion 28. Immediately beyond the latter is a"portion 21 which is substantially the same diameter as the pintleportion 28 supported in the end projecting part 23 of the casing half2|. The

pintle terminates .at its right-hand end in a threaded portion 22.Surrounding the pintle portions 21 and 82, respectively, are the innerraces 40 and ll of tapered roller bearings 42 and 42, the outer races 44and 4! of which are mounted in depressions l2 and 41 in the oppositeends of a cylinder barrel or primary rotor 42. The latter at,

its central portion closely surrounds thevpintle portion 82, and isprovided with radial cylinder bores 42 communicating with the cutawayportions 24 and 2! of the pintle 2!, and having pistons ll reciprocabietherein.

The pistons 52 are provided with rounded outer ends II which are adaptedto serve as crossheads enlailnl the segmental crosshead guide blocks. 52in the tapered recesses 62 thereof (Figures i2 and '13). An arcuategroove l4 traverses each segmental guide block from one end to theother. The peripheral surface ll of each segmental guide block l2 isrounded, or otherwise relieved at its ends so as to provide for the easymotion of the guide blocks 82 as they move to and fro during theoperation of the pump or motor. The cylinder barrel 42 is provided witha series of segmental ridges 56, extending between the cylinder ,bores49 and adapted to provide additional support for the pistons I0 duringtheir reciprocation. The grooves 84 in the guide blocks I2 are providedto enable the guide blocks to pass easily over the ridges 58-, as shownin Figure 6.

The .peripheral surfaces ll of the segmental guide blocks I2 engageanti-friction bearing elements, such as .the rollers 51, these (in turn,engaging the inner surface 58 of, the shift ring 59, the latter servingas an outer bearing race. The rollers 51 are maintained in position byretaining rings 60 resting in the recesses Si in the shift ring 59, andhaving annular grooves 82 engaging the corresponding projections 83 onthe ends of the rollers 51. At the top andbottom thereof the shift ring59 is provided with flattened portions 84 and 65, respectively engagingthe corresponding flattened portions 86 and, 61 of the casing half 2i. Athe opposite ends of its horizontal diameter the shift ring 59 isprovided with fiattened portions 68 and 69. 'The ,fiattened portion 88is engaged by a coil spring 10, mounted in a boss 1|, having a threadedbore 12 closed by a threaded adjusting plug 13. By varying the positionof the plug 13in the threaded bore 12 the tension of the spring 10 isadjusted. The flattened portion 89, however, isengaged by one end.

of a pilot piston 14, reciprocating in a cylinder bore 15 in a boss 18of the casing half 2|. The cylinder bore 15 is provided with a threadedoutlet port", in which is secured the end of the pilot line It leadingfrom the pressure outlet side of the pump.

The threaded portion 22, at the inner end of the pintle 2!, is providedwith a nut 1| and a lockwasher 12 adapted to engage the inner race 40 ofthe tapered roller bearing 42. A keyway I! is also provided in thethreaded end portion is,

and extends into the pintle portion 81. A key (not shown) within thekeyway 80 engages a corresponding slot in the loclrwasher 19 andprevents it from rotating, and at the same time the ear extending fromthe lockwasher 19 engages one of the flat sides of the nut 18 andprevents the rotation of the latter. The opposite or outer end of thepintle 25 is similarly provided with a threaded portion", having akeyway '22 therein. A key within the keyway 22 engages a correspondingslot in the lockwasher l5 and prevents the lockwasher from turning,whereas the ear on the lockwasher engages the flat side of the nut 22,threaded upon the threaded portion s2, and prevents the rotation of thenut.

Ky turning the nut with the lockwasher ll released, the pintle 2! may bemade to move longitudinally to adjust the clearances of the taperedroller bearings 42 and-ll. When, for

. example, the pintle 2I,is moved to the left, the

nut 12 and its lockwasher 1. push the inner race 40 against the rollers42, and the latter push the outer race I and the cylinder barrel 42 tothe left; This action closes the clearances existingbetween the rollers42 and the inner and outer bearing races II and ll, the inner bearing 7race ll being kept from moving by its engagement with the inner wall ofthe casing half 2|. After this adjustment is made the lockwasher ll mayv be bentto lock the nut 22 in the position of adjustment. The casinghalf 22 of the main pump II is provided with a recess 21 in which ismounted the'outer race ll of a ball bearing I,

the inner race so of which is mountedupon the enlargement ll of thedrive shaft 9:. The latter is provided with a further enlarged portion22, which is secured to the cylinder barrel 0 by means of the screws 04(Figure 6).

P I'Y-charginfl P mp pair of end plates ll and s2, spaced apart from-threaded plugs I06, I01, I08 and I09 (Figure 6).

The outer end of the stub shaft I03 extends into the socket H0 in thethreaded plug 109, whereas the main drive shaft 92 passes through thethreaded plug I01. The end plate 95 of the I super-charging pump II isjoined to the casing respectively.

half as of the main pump it by means of the machine bolts Hi. i

The dowel pins i i2 assist. in maintaining accurate alignment betweenthe end plates 95 and 98 and the spacing ring 97 (Figure 6). The

spacingring 91 is provided'with an intake passage H3 and an outletpassage H4, these terminating in the junction members Band 6, secured tothe opposite sides of the spacing ring 9! by the machine screws iii. Thejunction members H5 and iii are provided with threaded bores H8 and H 9,adapted to receive the threaded ends of the intake and outlet pipes i2and i3,

The modified construction shown in Figure 16 is similar to that shown inFigure 6', except that a pin I20 passes through a transverse hole 52! inthe crosshead guide block 52, and likewise passes through, a hole 122 inthe piston 50. Consequently, by this construction the pisconnection.

Operation In the operation of the pump assembly of this invention, poweris appliedto the drive shaft 92 from any convenient source, such as anelectric motor. The rotation of the drive shaft 92 causes the rotationof the pump gears 99 and I00, and in turn, causes fluid to bedrawn fromthe tank (not shown) through the intake line i2, and discharged throughthe outlet line it. The fluid passes from the outlet line I! of thesuper-charging pump il into the inlet passage 21 of the main pump i0,thence through the pintle passage 3| and the cutaway portion 35, intothe various cylinder bores 69 as these present themselves opposite thecutaway portion 35.

When theshift ring 59 is moved laterally so that its axis is eccentricto that of the pintle 25, the pistons'5li reciprocate in their cylinderbores when the rotation of the drive shaft ,92 rotates the primary rotoror cylinder barrel 58. As the pistons reciprocate their rounded ends 5|engage the tapered recesses 53 in the segmental guide blocks 52, and thelatter will 'move in an annular path with their peripheral surfaces 55engaging the rollers 5?, approaching the center of the pump duringone-half of the revolution and receding during the other half. Thepressure from the branch line 14 through the relief valve l5, into thedischarge line l6, and thence bac tothe tank.

The reciprocation of the pistons 50 within the main pump I 0 in thismanner causes pressure fluid to be discharged from the outlet line Il'thereof, and this fluid passes onward to the machinery or circuit whichit is intended to operate. If thefluid pressure rises beyond apredetermined point, the fluid reaching the pilot cylinder 15 throughthe branch line l8 acts upon the pilot piston 14 (Figure 7), urgingit tothe left and with it the shift ring 59, thereby overcoming the thrust ofthe coil spring 10. This action tends to return the shift ring 59 to itsneutral position and reduce the discharge of the pump.

It will Ice-understood that I desire to comprehend within my inventionsuch modifications as come within the scope of the claims and theinvention.

Having thus fully described my invention,

what I claim as new and desire to secure by Let- 'means for supplyingpressure fluid tothe pistons in said cylinder bores to maintain them insaid contacting engagement with said guide blocks during the suctionstrokes thereof.

2. A pump assembly comprising a casing, a

pintle, a cylinder. barrel with radial cylinder bores, pistonsreciprocable therein, segmental guide blocks adapted to have contactingengagement with the outer ends of the pistons, a shiftmember,anti-friction bearing elements arranged between said shift memberand said guide blocks, said anti-friction bearing elements being securedto said shift member in an annular path therearound and having theirinner portions exposed for direct-engagement by said guide blocks, andan auxiliary pump adapted to supply pressure fluid to the pistons tomaintain them in said contacting engagement with the guide blocksduringthe suction strokes thereof. L

3. A fluid pressure pump or motor comprising a'cylinder barrel havingcylinder bores, pistons reciprocable therein, a segmental guide blockfor each piston, a shift member, and anti-friction bearing elementsdirectly engaged by and ar-. ranged between said guide blocks and saidshift member, said anti-friction. bearing elements being secured to saidshift member in an annular path therearound and having their innerportions exposed for direct engagement by said guide blocks. I

4. A fluid pressure pump or motor comprising a cylinder barrel havingcylinder bores, "pistons reciprocable therein, a segmental guide blockfor each piston, a shift member, and anti-friction bearing elementsdirectly engaged by and arranged between said guide blocks' and saidshift member, said anti-friction bearing elements being secured to saidshift member in an annular path therearound' and having their innerportions exposed for direct engagement by said guide blocks,said-pistons having rounded ends and said guide blocks having recessesadapted to receive said rounded ends.

5. A fluid pressure pump or motor comprising acylinder barrel havingcylinder bores, pistons reciprocable therein, a segmental guide blmk foreach piston,'a shift member, and anti-friction bearing elements directlyengaged by and arranged between said guide blocks and said shift member,said anti-friction bearing elements being secured to said shift memberin an annular path therearound and having their inner portions exposedfor direct engagement by said guide.

blocks, said' pistons having contacting engagement with said guideblocks, and means for supplying pressure fluid to said pistons tomaintain said pistons against said guide blocks and said guide blocksagainst said bearing elements during the suction stroke. a

6. A fluid pressure pump or motor comprising a cylinder barrel havingcylinder bores, pistons reciprocable therein, a segmental guide blockfor each piston, a shift member, and anti-friction bearing elementsdirectly engaged by and arranged between said guidebloclrs and saidshift member, said anti-friction bearing elements being secured to saidshift member in an annular path therearound and having their innerportions exposed for direct engagement by said guide blocks, saidsegmental guide blocks being spaced apart from each other in acircumferential d1? rection. 4

7. A fluid pressure pump or motor comprising a cylinder barrel havingcylinder bores, pistons reclprocable therein, a segmental guide blockfor.

each piston, a shift member, anti-frictionbearing elements directlyengaged by and arranged between said guide blocks and said shift member,said anti-friction bearing elements being secured to said shift memberin an annular path there-- around and having their inner portionsexposed for-direct engagement by said guide blocks, and means forretaining said bearing elements in association with said shift member.

8. A fluid pressure pump or motor comprising a cylinder barrel havingcylinder bores, pistons reciprocable therein, a segmental guide blockfor each piston, a shift member, anti-friction bearing elements directlyengaged by and arranged between said guide blocks and said shift member,said anti-friction bearing'elements being secured to said shift memberin an annular path therearound and having their inner portions'exposedfor direct engagement by said guide blocks, and retaining memberssecured to said shift member to retain said bearing elements inassociation therewith. I

9. A fluid pressure pump or motor comprising a casing. a pintle therein,a cylinder barrel rotatably supported on said pintle, pistonsreciprocable radially in said cylinder barrel, each piston having anoutwardly disposed head, a shift member with orbitally disposedanti-friction bearing elements, and segmental guide blocks arrangedbetween and directly engflins said bearing elements and said pistonheads, said anti-friction bearing elements b01 8 secured to said shiftmember in an annular path with the outer portions thereof ensaging saidshift member and with the inner portions thereof exposed for directengagement by said guide blocks.

10. A fluid pressure pump or motor comprising a casing, a pintletherein, a cylinder barrel rotatably supported on said .pintle, pistonsreciprocable radially in said cylinder barrel, each piston having arounded head, a shift member with orbitally disposed anti-frictionbearing elements, and segmental guide blocks arranged between anddirectly engaging said bearing elements and said piston heads, saidanti-friction bearing elements being secured to said shift member in anannu-.

lar path with the outer portions thereof engaging said shift member andwith the inner portions thereof exposed for direct engagement by saidguide blocks, said segmental guide blocks 11. A fluid pressure pump ormotor comprising a casing, a pintle therein, a cylinder barrelrotatablysupported on said pintle, pistons reciprocable radially in saidcylinder barrel, each piston having an outwardly disposed head, a shiftmember supported by said casing for lateral movement relatively to saidpintle, anti-friction bearing elements carried by. said shift member,and segmental guide blocks arranged between and directly engaging saidbearing elements and saidpiston heads, said anti-friction bearingelements being secured to said shift member in an annular path with theouter portions thereof engaging said shift member and with the innerportions thereof exposed for direct engagement bysaid guide blocks. F

12. A fluid pressure pump or motor comprising a casing, a pintletherein, a cylinder barrel rotatably supported on said pintle, pistonsreciprocable radially in said cylinder barrel, each piston having anoutwardly dbpoeed head, a shift member supported by said casing forlateral movement relatively to said pintle, anti-friction bearingelements carried by said shift member, segmental guide blocks arrangedbetween and directly enusing said bearing elementseand said pistonheads, said anti-friction bearing elements being secured to said shiftmember in an annular path with the outer portions-thereof engaging saidshift member and with the inner portions thereof exposed for directengagement by said guide blocks, and retaining means secured to saidshift ring to maintain said bearing elements in asso ciation therewith.

' WALTER IRNB'I.

having recesses arranged to receive said rounded piston heads.

